#include <learnopengl/shader_s.h>
#include <GLFW/glfw3.h>
#include <stb_image.h>

#include <glm/glm.hpp>
#include <glm/gtc/matrix_transform.hpp>
#include <glm/gtc/type_ptr.hpp>

void framebuffer_size_callback(GLFWwindow *window, int width, int height) {
    glViewport(0, 0, width, height);
}

int main() {
    glfwInit();

    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
    glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);

    GLFWwindow *window = glfwCreateWindow(800, 600, "coordinate systems multiple", NULL, NULL);

    glfwMakeContextCurrent(window);
    glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);

    if (!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress)) {
        return -1;
    }

    glEnable(GL_DEPTH_TEST);

    Shader ourShader("shader.vs", "shader.fs");

    float vertices[] = {
        // -0.5f, -0.5f, -0.5f,                0.0f, 0.0f,
        //  0.5f, -0.5f, -0.5f,                1.0f, 0.0f,
        //  0.5f,  0.5f, -0.5f,                1.0f, 1.0f,
        //  0.5f,  0.5f, -0.5f,                1.0f, 1.0f,
        // -0.5f,  0.5f, -0.5f,                0.0f, 1.0f,
        // -0.5f, -0.5f, -0.5f,                0.0f, 0.0f,
        
        // -0.5f, -0.5f,  0.5f,                0.0f, 0.0f,
        //  0.5f, -0.5f,  0.5f,                1.0f, 0.0f,
        //  0.5f,  0.5f,  0.5f,                1.0f, 1.0f,
        //  0.5f,  0.5f,  0.5f,                1.0f, 1.0f,
        // -0.5f,  0.5f,  0.5f,                0.0f, 1.0f,
        // -0.5f, -0.5f,  0.5f,                0.0f, 0.0f,

        // -0.5f,  0.5f,  0.5f,                1.0f, 0.0f,
        // -0.5f,  0.5f, -0.5f,                1.0f, 1.0f,
        // -0.5f, -0.5f, -0.5f,                0.0f, 1.0f,
        // -0.5f, -0.5f, -0.5f,                0.0f, 1.0f,
        // -0.5f, -0.5f,  0.5f,                0.0f, 0.0f,
        // -0.5f,  0.5f,  0.5f,                1.0f, 0.0f,

        //  0.5f,  0.5f,  0.5f,                0.0f, 1.0f,
        //  0.5f,  0.5f, -0.5f,                1.0f, 1.0f,
        //  0.5f, -0.5f, -0.5f,                0.0f, 1.0f,
        //  0.5f, -0.5f, -0.5f,                0.0f, 1.0f,
        //  0.5f, -0.5f,  0.5f,                0.0f, 0.0f,
        //  0.5f,  0.5f,  0.5f,                1.0f, 0.0f,
         
        // -0.5f, -0.5f, -0.5f,                0.0f, 1.0f,
        //  0.5f, -0.5f, -0.5f,                1.0f, 1.0f,
        //  0.5f, -0.5f,  0.5f,                1.0f, 0.0f,
        //  0.5f, -0.5f,  0.5f,                1.0f, 0.0f,
        // -0.5f, -0.5f,  0.5f,                0.0f, 0.0f,
        // -0.5f, -0.5f, -0.5f,                0.0f, 1.0f,

        // -0.5f,  0.5f, -0.5f,                0.0f, 1.0f,
        //  0.5f,  0.5f, -0.5f,                1.0f, 1.0f,
        //  0.5f,  0.5f,  0.5f,                1.0f, 0.0f,
        //  0.5f,  0.5f,  0.5f,                1.0f, 0.0f,
        // -0.5f,  0.5f,  0.5f,                0.0f, 0.0f,
        // -0.5f,  0.5f, -0.5f,                0.0f, 1.0f

        -0.5f, -0.5f, -0.5f,  0.0f, 0.0f,
         0.5f, -0.5f, -0.5f,  1.0f, 0.0f,
         0.5f,  0.5f, -0.5f,  1.0f, 1.0f,
         0.5f,  0.5f, -0.5f,  1.0f, 1.0f,
        -0.5f,  0.5f, -0.5f,  0.0f, 1.0f,
        -0.5f, -0.5f, -0.5f,  0.0f, 0.0f,

        -0.5f, -0.5f,  0.5f,  0.0f, 0.0f,
         0.5f, -0.5f,  0.5f,  1.0f, 0.0f,
         0.5f,  0.5f,  0.5f,  1.0f, 1.0f,
         0.5f,  0.5f,  0.5f,  1.0f, 1.0f,
        -0.5f,  0.5f,  0.5f,  0.0f, 1.0f,
        -0.5f, -0.5f,  0.5f,  0.0f, 0.0f,

        -0.5f,  0.5f,  0.5f,  1.0f, 0.0f,
        -0.5f,  0.5f, -0.5f,  1.0f, 1.0f,
        -0.5f, -0.5f, -0.5f,  0.0f, 1.0f,
        -0.5f, -0.5f, -0.5f,  0.0f, 1.0f,
        -0.5f, -0.5f,  0.5f,  0.0f, 0.0f,
        -0.5f,  0.5f,  0.5f,  1.0f, 0.0f,

         0.5f,  0.5f,  0.5f,  1.0f, 0.0f,
         0.5f,  0.5f, -0.5f,  1.0f, 1.0f,
         0.5f, -0.5f, -0.5f,  0.0f, 1.0f,
         0.5f, -0.5f, -0.5f,  0.0f, 1.0f,
         0.5f, -0.5f,  0.5f,  0.0f, 0.0f,
         0.5f,  0.5f,  0.5f,  1.0f, 0.0f,

        -0.5f, -0.5f, -0.5f,  0.0f, 1.0f,
         0.5f, -0.5f, -0.5f,  1.0f, 1.0f,
         0.5f, -0.5f,  0.5f,  1.0f, 0.0f,
         0.5f, -0.5f,  0.5f,  1.0f, 0.0f,
        -0.5f, -0.5f,  0.5f,  0.0f, 0.0f,
        -0.5f, -0.5f, -0.5f,  0.0f, 1.0f,

        -0.5f,  0.5f, -0.5f,  0.0f, 1.0f,
         0.5f,  0.5f, -0.5f,  1.0f, 1.0f,
         0.5f,  0.5f,  0.5f,  1.0f, 0.0f,
         0.5f,  0.5f,  0.5f,  1.0f, 0.0f,
        -0.5f,  0.5f,  0.5f,  0.0f, 0.0f,
        -0.5f,  0.5f, -0.5f,  0.0f, 1.0f
    };

    // world space positions of our cubes
    glm::vec3 cubePositions[] = {
        glm::vec3( 0.0f,  0.0f, -1.5f),
        glm::vec3( 2.0f,  5.0f, -15.0f),
        glm::vec3(-1.5f, -2.2f, -2.5f),
        glm::vec3(-3.8f, -2.0f, -12.3f),
        glm::vec3( 2.4f, -0.4f, -3.5f),
        glm::vec3(-1.7f,  3.0f, -7.5f),
        glm::vec3( 1.3f, -2.0f, -2.5f),
        glm::vec3( 1.5f,  2.0f, -2.5f),
        glm::vec3( 1.5f,  0.2f, -1.5f),
        glm::vec3(-1.3f,  1.0f, -1.5f)
    };

    unsigned int VBO, VAO;
    glGenVertexArrays(1, &VAO);
    glGenBuffers(1, &VBO);

    glBindVertexArray(VAO);

    glBindBuffer(GL_ARRAY_BUFFER, VBO);
    glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);

    // position attribute
    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 5 * sizeof(float), (void*)0);
    glEnableVertexAttribArray(0);

    glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 5 * sizeof(float), (void*) (3 * sizeof(float)));
    glEnableVertexAttribArray(1);

    // load and create a texture
    unsigned int texture1, texture2;

    // texture 1
    glGenTextures(1, &texture1);
    glBindTexture(GL_TEXTURE_2D, texture1);

    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);

    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);

    // load image, create texture and generate mipmaps
    int width, height, nrChannels;
    stbi_set_flip_vertically_on_load(true);
    unsigned char* data = stbi_load("container.jpg", &width, &height, &nrChannels, 0);
    if (data) {
        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width, height, 0, GL_RGB, GL_UNSIGNED_BYTE, data);
        glGenerateMipmap(GL_TEXTURE_2D);
    }

    stbi_image_free(data);

    // texture 2
    glGenTextures(1, &texture2);
    glBindTexture(GL_TEXTURE_2D, texture2);

    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);

    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);

    data = stbi_load("awesomeface.png", &width, &height, &nrChannels, 0);
    if (data) {
        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, data);
        glGenerateMipmap(GL_TEXTURE_2D);
    }

    stbi_image_free(data);

    ourShader.use();
    ourShader.SetInt("texture1", 0);
    ourShader.SetInt("texture2", 1);

    while(!glfwWindowShouldClose(window)) {
        glClearColor(0.2f, 0.3f, 0.3f, 1.0f);
        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

        glActiveTexture(GL_TEXTURE0);
        glBindTexture(GL_TEXTURE_2D, texture1);

        glActiveTexture(GL_TEXTURE1);
        glBindTexture(GL_TEXTURE_2D, texture2);

        ourShader.use();

        glm::mat4 view = glm::mat4(1.0f);
        glm::mat4 projection = glm::mat4(1.0f);
        projection = glm::perspective(glm::radians(45.0f), 800.0f / 600.0f, 0.1f, 100.0f);
        view = glm::translate(view, glm::vec3(0.0f, 0.0f, -3.0f));

        ourShader.SetMat4("projection", projection);
        ourShader.SetMat4("view", view);

        // render boxes
        glBindVertexArray(VAO);
        for (unsigned int i = 0; i < 10; i++) {
            glm::mat4 model = glm::mat4(1.0f);
            model = glm::translate(model, cubePositions[i]);
            float angle = 20.0f * i;
            if(i % 2 == 0)  // every 3rd iteration (including the first) we set the angle using GLFW's time function.
                angle = glfwGetTime() * 25.0f;
            model = glm::rotate(model, glm::radians(angle), glm::vec3(1.0f, 0.3f, 0.5f));
            ourShader.SetMat4("model", model);

            glDrawArrays(GL_TRIANGLES, 0, 36);
        }

        glfwSwapBuffers(window);
        glfwPollEvents();
    }

    glDeleteVertexArrays(1, &VAO);
    glDeleteBuffers(1, &VBO);

    glfwTerminate();
    return 0;
}